CONFIGURATION

The dsp56k device is a character device with major number 55 and minor
number 0.

DESCRIPTION

The Motorola DSP56001 is a fully programmable 24-bit digital signal
processor found in Atari Falcon030-compatible computers. The
dsp56k special file is used to control the DSP56001, and
to send and receive data using the bi-directional handshaked host
port.

To send a data stream to the signal processor, use write() to the
device, and read() to receive processed data. The data can be sent or
received in 8, 16, 24, or 32-bit quantities on the host side, but will
always be seen as 24-bit quantities in the DSP56001.

resets the DSP56001 and uploads a program. The third ioctl() argument
must be a pointer to a struct dsp56k_binary with members
bin pointing to a DSP56001 binary program, and len set to
the length of the program, counted in 24-bit words.

DSP56K_SET_TX_WSIZE

sets the transmit word size. Allowed values are in the range 1 to 4,
and is the number of bytes that will be sent at a time to the
DSP56001. These data quantities will either be padded with zero
bytes, or truncated to fit the native 24-bit data format of the
DSP56001.

DSP56K_SET_RX_WSIZE

sets the receive word size. Allowed values are in the range 1 to 4,
and is the number of bytes that will be received at a time from the
DSP56001. These data quantities will either truncated, or padded with
a zero byte to fit the native 24-bit data format of the DSP56001.

DSP56K_HOST_FLAGS

read and write the host flags. The host flags are four
general-purpose bits that can be read by both the hosting computer and
the DSP56001. Bits 0 and 1 can be written by the host, and bits 2 and
3 can be written by the DSP56001.

To access the host flags, the third ioctl() argument must be a pointer
to a struct dsp56k_host_flags. If bit 0 or 1 is set in the
dir member, the corresponding bit in out will be written
to the host flags. The state of all host flags will be returned in
the lower four bits of the status member.

DSP56K_HOST_CMD

sends a host command. Allowed values are in the range 0 to 31, and is a
user-defined command handled by the program running in the DSP56001.